Risk of Acute Kidney Injury after Intravenous Contrast Media Administration in Patients with Suspected Pulmonary Embolism: A Propensity-Matched Study

Abstract

Abstract Background Although computed tomography pulmonary angiography (CTPA) is the preferred diagnostic procedure in patients with suspected pulmonary embolism (PE), some patients undergo ventilation/perfusion (V/Q) lung scan due to concern of contrast-associated acute kidney injury (AKI). Methods The study used a cohort of 4,565 patients with suspected PE. Patients who received contrast during CTPA were compared with propensity score-matched unexposed control patients who underwent V/Q lung scanning. AKI was defined as ≥50% increase in serum creatinine during the first 72 hours after either CTPA or V/Q lung scan. Results Classification and regression tree analysis demonstrated that baseline creatinine was the strongest determinant of the decision to use CTPA. Propensity-score matching yielded 969 patient pairs. There were 44 AKI events (4.5%) in patients exposed to contrast media (CM) and 33 events (3.4%) in patients not exposed to CM (risk difference: 1.1%, 95% confidence interval [CI]: −0.6 to 2.9%; odds ratio [OR]: 1.39, 95% CI: 0.86–2.26; p = 0.18). Using different definitions for AKI and extending the time window for AKI diagnosis gave similar results. In a sensitivity analysis with the inverse probability weighting method, the OR for AKI in the CTPA versus V/Q scan was 1.14 (95% CI: 0.72–1.78; p = 0.58). Conclusion Intravenous contrast material administration was not associated with an increased risk of AKI in patients with suspected PE. Given the diagnostic superiority of CTPA, these results are reassuring with regard to the use of CTPE in patients with suspected PE perceived to be at risk for AKI.